Parameter estimation for suspended sediment transport processes under random waves

摘要

This paper presents a parameter estimation method for suspended sediment transport processes subject to random wave environments. An objective function was constructed based on measurements of suspended sediment concentration profiles and the governing equation of sediment transport. The Chebyshev least square method was employed to approximate the process parameters, i.e. vertical eddy diffusivity (ε) and net vertical velocity (w). The objective function of sediment transport processes with Chebyshev's parameters is well posed and does not require boundary conditions. First, second, and third order ε and w Chebyshev orthogonal functions were determined for monochromatic (MONO), narrow-banded (NBR) and broad-banded (BBR) random wave conditions. In the BBR and NBR conditions, the best fit Chebyshev approximations of ε and w were 2nd degree, while the best approximations in the MONO condition were 2nd degree for ε and 1st degree for w. The Chebyshev method provides a quick, accurate and direct estimation of two prime parameters in sediment transport dynamics.